1. Field of the Invention
The invention relates to a system for controlling the pH balance of a body of water or pool within a given range, for example the chlorine and pH balance of a swimming pool, through monitoring the operational time of a salt chlorine generator in the chlorination system and calculating an estimated pH based in whole or in part on this variable.
2. Background of the Invention
Recreational pools such as swimming pools, spas and hot tubs provide a great deal of pleasure and comfort. Similarly, landscaping often incorporates bodies of water for a pleasing aesthetic. The extent of aesthetic beauty or comfort depends on the quality of the water. In order to assure comfort and safety to users of these pools, it is important that the water be treated properly so that it is aesthetically pleasing in terms of taste, color, turbidity and odor. Proper treatment also is important so that the water has proper pH, and is environmentally safe as well as effectively free of pathogens and chemicals which may cause illness.
Many systems have been designed for controlling the chemical balance of swimming pools and the like. Several systems have sought patent protection, including the following:
Pat. No.Inventor(s)3,804,253Wellman et al.4,224,154Steininger4,381,240Russell4,657,670Newton5,019,250Lorenzen5,277,802Goodwin5,320,748Dupuis6,125,481Sicilano6,309,538Khan7,167,087Corrington et al.7,291,261Rhodes2001/0045380Khan2005/0137118Silveri2005/0194296Lin2006/0283811Unhoch2007/0012631Coffey et al.FR 27-85898GiroguyJP 81-89217Yamagata
For the most part, simple, inexpensive systems performing this function automatically dispense pre-set amounts of chemicals into the pool at pre-set intervals or through other processes such as salt-chlorine generation. Maintaining the chemical balance of a swimming pool is quite important. If the chemical balance departs from a given range, unsanitary conditions will develop permitting algae and bacteria to grow and contaminate the pool. If such conditions exist for long, they may require the pool to be drained and acid washed. Improperly high chlorine or other chemicals and resulting pH levels can cause eye and skin irritations to swimmers, as well as pipe corrosion or scaling to the recirculation system, giving rise to increased operating and heating costs due largely to the resultant inefficiencies.
To operate properly these systems generally require consistent monitoring on the part of the pool owner to maintain proper operation and proper chemical balance within the pool. Even when properly monitored, in the case of salt chlorine generators, the sanitation process can dramatically change the pH level within the body of water or pool being sanitized. Similarly, conditions such as pool usage, weather, temperature, and other environmental factors can also change the pH balance in the body of water.
The more expensive, elaborate versions of such pool treatment systems can sense the chemical balance of the pool, and dispense chemicals to maintain the pH balance of a pool with a given range. Most use probes or sensors that detect the pH levels and then dispense acid accordingly. They are generally quite expensive and are plagued with field calibration issues and probe and sensor failure. Moreover, because of their elaborate nature such systems only are economical for large, heavily used pools. Even when used in such pools, they require additional and significant maintenance of the sensors in the pool and the system communicating the readings from these sensors to such systems.
There is a need for an automatic chemical control system for a swimming pool, one which is relatively simple in construction and durable in operation. Such a system would provide significant safety and a real convenience to the pool owner, reducing maintenance costs and permitting extended periods of operation with little or no need for adjustment or attention. The system described herein meets these objectives, as well as other objectives which will be apparent to those skilled in the art upon reading the following detailed description.